WaveRx Inc.'s head slipped under the water forever, a victim of its backers' doubts about the FDA ever giving a green light to its technology for treating diabetic neuropathy. Mark Wan, a founding partner at Three Arch Partners, told the VentureWire blog that his VC company and its two other partners in WaveRx, 5AM Ventures and Polaris Venture Partners, shut the taps last year after waiting for an answer from the FDA's Center for Devices & Biological Health about its proposal for a re-vamped clinical trial.